The current G12 member states are:
The Group of Twelve or G12 is a group of industrially advanced countries whose central banks co-operate to regulate international finance.
Note that the G-12 consists of thirteen countries. It encompasses the initial ten members of the International Monetary Fund (IMF), which formed the original G10, adding Australia and Spain. In 1984, when Switzerland joined the G10 and G12, the names of the groups were not changed.